Despite the fact that the 19th century is in the yard and almost any information about many issues of interest is freely available, the question of whether an ovulation test can show pregnancy remains one of the most common. Many women are sure that this is quite possible. Is this so, we will answer in this article.
How does the test work?
For ovulation
Before talking about whether the ovulation test system shows the "interesting" situation that has come, it is worthwhile to figure out what, in fact, is the similarity and difference between pregnancy tests and similar systems for ovulation.
Test systems for determining ovulation (the period of release of a mature egg from the follicle) are created for planning pregnancy and contraception.
They allow a woman to better understand the boundaries of her fertile window - the period when the probability of conception is greatest.
The process of ovulation in a woman's body is accompanied and regulated by certain hormonal support, without which neither ovulation nor menstruation would simply occur. In the first half of the menstrual cycle, it produces a large amount of estrogen, which blocks the production of progesterone. Under the influence of follicle-stimulating hormone (FSH), the dominant follicle matures and increases in size, from which the egg cell ready for fertilization should appear on the right day.
The required day is determined by the concentration of another hormone - LH (luteinizing)... The peak concentration of this substance occurs in the period immediately before ovulation.
All of these substances accumulate in the blood, and therefore can be determined by laboratory blood tests. But for ease of diagnosis, so-called home ovulation tests are widely used today.
They range from strip strips for dipping in urine to expensive electronic mini-microscopes for diagnosing salivary fluid and vaginal secretions. With the second strip, these systems (strip, cassette) react to the presence of a sufficient concentration of luteinizing hormone (LH) in the woman's urine. In this way, two strips on the ovulation test - a sign of approaching a crucial period, when the conception of a baby is most likely.
Mini microscopes do not respond to LH, but to estrogen levels. At its high concentration (the peak also falls on the period before ovulation), when dry, saliva crystallizes in a certain pattern, resembling fern leaves.
After the end of the fertile period, ovulation test systems usually show negative results again.
A second strip on ovulation test systems appears in the area where the luteinizing hormone sensitive reagent is applied. Actually, the very fact of the presence of a second stripe is the only similarity between the ovulation test and a similar device for determining pregnancy. Two stripes - the result is positive. The principle of operation is also almost identical, but the reagents and targets are different.
For pregnancy
The well-known test strips, as well as electronic devices that allow you to answer the question of whether a woman is pregnant or not, also respond to the hormone, but to a completely different system than the ovulation system.
After conception, the embryo, without stopping to split, descends into the uterine cavity, where after about a week it is implanted into the uterine wall. Chorionic villi, with which the embryo is immersed in the endometrial tissue, immediately begin to produce a special hormone - hCG (human chorionic gonadotropic hormone). The concentration of this substance in a woman's blood doubles every two days.
The hormone is needed by the body of the expectant mother and baby, because it allows you to maintain a consistently high level of progesterone, which ensures the viability of the embryo, its nutrition, and the creation of optimal conditions for its growth and development. HCG reaches peak values by 12 weeks of pregnancy, and then begins to gradually decrease.
Since the level of the hormone increases gradually, it begins to be determined in a woman's urine by the beginning of the delay, or even in the first days after it (in the blood - earlier, on which, in fact, the blood test for hCG is based). Pregnancy test systems are strips with a hCG-sensitive test area.
If the concentration of chorionic gonadotropin exceeds the sensitivity level of the test, a clear second strip appears, which gives the right to assert that the woman is pregnant.
What exactly will show a successful conception?
As the name suggests, pregnancy is shown with high accuracy by a system that has a sensitive zone specifically to chorionic gonadotropin, that is, a pregnancy test that can be used both shortly before the delay and after it.
Ovulation test systems are not suitable for determining the fact of pregnancy., since they do not reliably respond to the presence of hCG in the urine, their sensitive zones react with a second strip to luteinizing hormone, which is almost absent in the second half of the cycle both during pregnancy and outside of it.
Thus, an ovulation test during pregnancy should normally show negative results.
These strips are different in their principle, reagents, and purposes of use. But the manufacturers of ovulation tests took care of women and prudently many place two strips with a sensitivity to hCG in a package with five ovulation strips. The five ovulation strips should be used mid-cycle to establish fertile days, and two strips of a pregnancy test - on the eve of a delay or on the first day of a delay in the next menstruation.
Possible errors
Judging by the feedback from women, ovulation test strips sometimes behave "strange" - showing two stripes just before the expected period. They are often mistaken for a sign of a possible pregnancy. Why might this be happening?
At the chemical level, the structure of chorionic gonadotropic hormone, which is produced during pregnancy, and luteinizing hormone, an invariable companion of ovulation in women, is largely similar, and therefore there is an approximately 20% chance that the reagents can be mutually "wrong"... The sensitivity of the ovulation systems is always significantly higher than the sensitivity of pregnancy tests, because LH in a favorable pre-ovulatory period is present in much lower amounts than hCG after embryo implantation. Therefore, traces can be caught by this test system.
Another question, how to treat a positive ovulation test if pregnancy is suspected. And you should treat it like a mistake.... Such a reaction of the ovulation strip to hCG is nothing more than a system error, a false positive result and cannot be evaluated as a diagnostic result.
If the ovulation test shows a persistent positive result throughout the second half of the cycle, a cross-reaction of the reagent to progesterone is possible, the level of which is high in the second phase of the female cycle.
In general, ovulation test systems are pretty cool stuff. Weak reactions like a fuzzy second strip, they can give out on the excess of thyroid-stimulating hormone, on the hormone FSH, on a number of molecules of pituitary hormones. And the fact is that in these hormones, the alpha particles are really similar, and the beta subunits are different. The pregnancy test is designed to "capture" the beta-subunits of hCG, and therefore, no matter how hard you try, they will not be able to determine ovulation... But in some cases (about 15-20%), a weak positive reaction of the ovulation system may well indicate the presence of certain hormones in the urine, usually pituitary. Pregnancy or thyroid pathology - the strip will help to answer, which, in fact, exists for this - a test system for determining pregnancy.
Reviews
Reviews of this use of ovulation tests are quite polar: some women believe that such a use of a test to determine ovulation is permissible, while others strongly disagree with this. Some cite that they used ovulation tests, because it was far from the pharmacy to buy a pregnancy test. Others point out that it is too expensive to use ovulation test strips for other purposes, because they are orders of magnitude more expensive than pregnancy tests.
Some managed to get a positive result, and a little later the pregnancy was confirmed. For some, ovulation tests have been negative if they are pregnant.
Doctors do not recommend taking the readings of ovulation test systems seriously if they are used for other purposes. This hobby can rather be attributed to a game or fortune telling, since such actions have absolutely nothing to do with medical diagnostics.
